• Spending: Between $1 million and $1.1 million, according to an AFP spokesman, to run for several weeks on digital platforms, and broadcast and cable television. AFP is a 501(c)(4) "dark money" group that is not required to disclose its donors or spending.

The conservative group Americans for Prosperity, based in a Washington, D.C., suburb in Virginia, released an ad Thursday attacking Begich for his U.S. Senate attendance record.

The group was founded by the billionaire industrialist Koch brothers, and advocates for lower taxes, less government and repealing the Affordable Care Act, also known as Obamacare.

The ad shows Steve Perrins, the owner of a hunting lodge in Rainy Pass, 125 miles northwest of Anchorage, chopping wood and telling viewers that "the Alaskan value system is hard work, taking care of yourself."

Perrins then accuses Begich of "not showing up for his job."

"Last year, Mark Begich missed more votes than 80 percent of all other U.S. senators," Perrins says.

First of all, the man in the ad is, in fact, Perrins. His wife, Denise Perrins, said in a phone interview Thursday that the ad had been filmed at Rainy Pass Lodge just after July 4.

"It's at our lodge here," she said. "They came out from Washington, D.C., and filmed it."

As for the ad's claim, Alaska Dispatch News ranked the voting records of the 97 senators who served through all of 2013, using data from the website GovTrack. There were 291 roll call votes that year, according to U.S. Senate records.

Begich missed 12, the 16th highest, tied with Mary Landrieu, D-La. Putting him in a conservative 17th place, that still means he missed more votes than 82 percent of his colleagues.

Begich, however, has the best attendance record of the three members of Alaska's congressional delegation.

Begich's career attendance record is also the Alaska delegation's highest, though the three members have served for different lengths of time. Begich has missed 4.5 percent of the votes in his nearly six years in office, compared to 4.7 percent for Murkowski over nearly 12 years, and 14.9 percent for Young over 41 years.

"Mark Begich has Alaska's best congressional attendance record and is always ready to go to work for Alaska. That means working in Washington, traveling thousands of miles across Alaska to listen to Alaskans and talking issues at Home Depot," spokesman Max Croes wrote in an emailed statement. "This ad proves the Koch brothers will say anything in their attempts to buy Alaska's Senate seat for (Republican opponent) Dan Sullivan."

Asked for examples of reasons Begich missed votes, Croes listed six community events in Alaska, including an Anchorage Chamber of Commerce meeting in May of last year.

He also missed a procedural vote early this year to deliver a speech to a lobbying group in Hawaii, where he held two fundraisers as well, according to The Hill, a Washington, D.C.- based website.

One other factor to consider is that members of the Alaska delegation face among the longest commutes of all their colleagues.

Sixteen members of the Senate had perfect voting records in 2013. The senator who missed the most votes was James Inhofe, R-Okla, at 41, or 14 percent. He had open-heart surgery last year.

Sen. Susan Collins, R-Maine, is the longest-serving member to not miss a single vote in her career. She has been serving since 1997 and has participated in 5,623 consecutive votes.